In a typical 1+1 protection switching arrangement, there are two communication units connected in a point to point configuration. One unit is configured as a central unit (also known as an STU-C), and the other as a remote unit (also known as an STU-R). Each unit is connected by two links. Both links carry identical traffic at the physical layer. However, only one link is considered active while the other link acts as backup. When there is a failure on the active link, a protection switch occurs making the backup link active. In this way, communication is not interrupted when a failure occurs on the active link.